This application claims the priority of German application 198 59 162.4, filed in Germany on Dec. 21, 1998, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to an arrangement for non-contact revolution counting of a spinning rotor arranged in a spinning aggregate, which spinning rotor is supported on supporting discs, of which one supporting disc is provided on an end face side with at least one permanent magnet, and a signal receiver of a maintenance device arrangeable at the spinning aggregate being disposable in operable position to detect the movement of the magnet.
An arrangement of this type is prior art in U.S. Pat. No. 5,675,964. A signal generator of the maintenance device can be placed adjacent to the relevant front side of the supporting disc holding the permanent magnet at a distance of between 3 to 6 mm. This requires not only a complicated design to make the supporting disc containing the permanent magnet accessible for the signal generator from the operator's side of the spinning aggregate, but also requires a high degree of exactness as regards the dimensions, as the distance between the permanent magnet and the signal generator must be reproduced exactly from spinning aggregate to spinning aggregate.
It is an object of the present invention to make the non-contact revolution counting of the above mentioned type accessible even in the case of less accessible supporting discs, and to make it to a great extent independent of work tolerances.
This object has been achieved in accordance with the present invention in that the distance between the permanent magnet and the signal receiver is bridged by a ferromagnetic information transmitter transmitting information about magnetic forces to the signal receiver.
By means of such a ferromagnetic information transmitter, with which older spinning machines can be equipped in a modernization process, the magnetic field lines of the supporting disc located in the inside of the spinning aggregate can be "transmitted" over to the operator's side of the spinning aggregate and guided to a point which is easily accessible for the piecing device. The ferromagnetic information transmitter can be advantageously arranged at each individual spinning aggregate, whereby the distance between the permanent magnet and the information transmitter can be predetermined exactly. It is purposeful hereby to arrange the ferromagnetic information transmitter to a housing section of the spinning aggregate which can be swivelled, as such housing sections are, as a rule, the most accessible to the maintenance device.
In a further advantageous feature of preferred embodiments of the invention, the ferromagnetic information transmitter takes the form of a metal strip adapted to the contour of the swivelling housing section. The ferromagnetic information transmitter does not act as an intrusive component, and a metal strip can be easily adapted to different contours by means of deformation. It is, of course, hereby important, that the ferromagnetic information transmitter is magnetically insulated against adjacent components, insofar as these are also ferromagnetic. For this reason, on the one hand a certain distance between the ferromagnetic information transmitter and the relevant component to which it is affixed is retained, as the air gap acts to insulate, while on the other hand, liners of aluminium or plastic, for example, are applied to the contact points.
It can be provided that the signal receiver is disposed directly on the ferromagnetic information transmitter during a maintenance period according to certain preferred embodiments of the invention. Should this not be possible, however, because for example the swivelling housing section does not permit such a position, the signal receiver can comprise an induction coil surrounding an iron core according to other preferred embodiments of the invention. Thus contact between the signal receiver and the ferromagnetic information transmitter is not absolutely necessary, as the iron core can transmit the magnetic field lines at any desired point to the signal receiver, for example outside of the swivel area of a swivelling housing section. In the case of such an embodiment according to the prese nt invention, the signal receiver can be stationarily affixed to the maintenance device, so that the signal receiver does not necessarily need to be advanced to the information transmitter by means of a relative motion.